Evaluation of screening methods for fungicides to control take-all of wheat

Three screening methods were used to evaluate the activity of eight fungicides against the saprophytic growth of Gaeumannomyces graminis var. tritici (Ggt) and its damage to wheat seedlings. Linear regression analyses were used to determine the relationships between the results of the different screening procedures. Control of saprophytic growth of Ggt either on agar or in soil, was not related to control of take-all on seedlings, sothat inhibition of saprophytic growth by a fungicide does not always indicate an ability to suppress take-all. Flutolanil, cyproconazole and SN-539865 were equal to, or better than, flutriafol (which is registered for control of the disease) in reducing take-all in wheat seedlings. This study has highligted discrepancies in different screening techniques and identified some new chemicals which show potential for controlling take-all.